New treatment targets toxic bacteria, `superbugs'

A new approach to fighting toxic bacteria could mean an end to the problem of drug-resistant "super-bugs," California researchers said Thursday.

They found a single protein that controls production of all the poisons that make staphylococcus bacteria dangerous and also found two ways to stop the protein's action.Naomi Balaban and colleagues at the University of California, Davis, said they hoped their new approach, which uses either a vaccine or a protein molecule, would provide an alternative to antibiotics.

"It's all by peaceful terms for the bacteria, so maybe it won't resist it as much," Balaban, an infectious-disease specialist, said in a telephone interview.

Staphylococcus aureus - staph for short - is the most common cause of infection in the United States. It causes infections ranging from harmless pimples to toxic shock syndrome.

Staph is usually easy to treat with antibiotics, but drug-resistant forms have evolved. Most frightening is a strain that resists vancomycin, the powerful antibiotic seen as the last line of defense against bacteria. Only three cases have been reported, but experts predict there will be more.

Balaban said her approach avoided the whole problem.

Writing in the journal Science, she said she found a way to stop the staph bacteria from producing the toxins that make it dangerous. "Unlike antibiotics, it does not kill the bacteria, so there is no pressure on the bacteria to mutate," she said.

There is no real need to kill the bacteria, she said.

"The bacteria doesn't necessarily cause disease because it enters the body but because of the toxins it produces," she said. She believes the toxins are meant to enhance the bacteria's survival.

Fighting each separate toxin would be unwieldy and time-consuming. So Balaban looked for a protein that controls all toxin production, and she found it.

"There is one protein that activates the cascade of events and activates many toxins, so all you have to deal with is the one protein," she said.